Spontaneous emission induced filamentation in flared amplifiers

We present a propagation model for the steady-state properties of InGaAs QW flared laser amplifiers. Included in this analysis are diffusion, diffraction, carrier induced antiguiding, current spreading, gain spatial hole burning, gain compression and spontaneous emission. By monitoring the progress of the field, as well as the carrier density, we show that spontaneous emission, coupled with gain spatial hole burning, can result in filamentation of the amplifier output. This mechanism is in addition to other phenomena such as thermal effects and reflective feedback which have been shown to cause filamentation.